| //===-- modsi3.S - 32-bit signed integer modulus --------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the __modsi3 (32-bit signed integer modulus) function |
| // for the ARM architecture as a wrapper around the unsigned routine. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "../assembly.h" |
| |
| #define ESTABLISH_FRAME \ |
| push {r4, r7, lr} ;\ |
| add r7, sp, #4 |
| #define CLEAR_FRAME_AND_RETURN \ |
| pop {r4, r7, pc} |
| |
| .syntax unified |
| .text |
| DEFINE_CODE_STATE |
| |
| @ int __modsi3(int divident, int divisor) |
| @ Calculate and return the remainder of the (signed) division. |
| |
| .p2align 3 |
| DEFINE_COMPILERRT_FUNCTION(__modsi3) |
| #if __ARM_ARCH_EXT_IDIV__ |
| tst r1, r1 |
| beq LOCAL_LABEL(divzero) |
| sdiv r2, r0, r1 |
| mls r0, r2, r1, r0 |
| bx lr |
| LOCAL_LABEL(divzero): |
| mov r0, #0 |
| bx lr |
| #else |
| ESTABLISH_FRAME |
| // Set aside the sign of the dividend. |
| mov r4, r0 |
| // Take absolute value of a and b via abs(x) = (x^(x >> 31)) - (x >> 31). |
| eor r2, r0, r0, asr #31 |
| eor r3, r1, r1, asr #31 |
| sub r0, r2, r0, asr #31 |
| sub r1, r3, r1, asr #31 |
| // abs(a) % abs(b) |
| bl SYMBOL_NAME(__umodsi3) |
| // Apply sign of dividend to result and return. |
| eor r0, r0, r4, asr #31 |
| sub r0, r0, r4, asr #31 |
| CLEAR_FRAME_AND_RETURN |
| #endif |
| END_COMPILERRT_FUNCTION(__modsi3) |
| |
| NO_EXEC_STACK_DIRECTIVE |
| |
